In recent years, a number of new telephone service features have been provided by an Advanced Intelligent Network (AIN). The AIN evolved out of a need to increase the capabilities of the telephone network architecture in order to meet the growing needs of telephone customers or users. Additionally, as the number of people who rely on the Internet for communication increases, so too does the demand for the electronic transfer of data.
Referring now to FIG. 1, it is seen that an AIN-based network arrangement is provided within and/or in conjunction with a wire line telephone system LATA (Local Access and Transport Area) 101 that defines a calling service area. Note that a similar arrangement is also provided with and/or in conjunction with a wireless telephone system. Each LATA 101 (only one being shown in FIG. 1) includes stations (i.e. telephone lines and telephone equipment at the respective ends thereof) 103 and corresponding service switching points (SSPs) 105 (i.e., end offices or central offices). The SSPs 105 are each programmable switches which: recognize AIN-type calls; launch queries to service control points (SCPs) 107 (only one being shown in FIG. 1); and receive commands and data from SCPs 107 to further process and route AIN-type calls. A signal transfer point (STP) 109 may be employed to route signals between the SSPs 105, the SCPs 107, and other network elements. When one of the SSPs 105 is triggered by an AIN-type call, the triggered SSP 105 formulates an AIN service request and responds to call processing instructions from the network element in which the AIN service logic resides, typically at an SCP 107.
One type of event that may be arranged to set off an AIN trigger in an SSP 105 or the like is a call from a calling party to a called party where the called party subscribes to a call forwarding service. Accordingly, the AIN trigger at issue is associated with the called party and with the SSP 105 of such called party. In response to the set-off trigger, the SSP 105 determines from the SCP 107 whether the call forwarding service has been actuated by the called party and if so routing instructions for forwarding the call as has already been arranged by the called party.
In one form of the aforementioned call forwarding service, the called party can set the call from the calling party to be forwarded from a wire line (i.e. land line) station to a wireless (i.e., mobile or cellular) station. More generally, though, the call forwarding service can encompass forwarding the call from the calling party from a wire line or wireless station to another wire line or wireless station.
In any case, the call forwarding service works such that when a calling party calls a service-subscribing called party, and assuming the service is actuated, the corresponding AIN trigger or the like is set off, the triggered SSP 105 or the like formulates and sends a service request to an SCP 107 or the like, and receives from the SCP 107 call processing instructions including a telephone number of a destination station to which the call is to be forwarded.
The SSP 105 then in fact forwards the call to the destination station, but must wait to see if the destination station is on (if a mobile or cellular station, e.g.), and to see if the call is in fact answered at such destination station. As may be appreciated, such waiting is costly in that multiple circuits may be continuously employed for the duration of the forwarding. In one scenario, for example, a calling party calls a service-subscribing called party at a wire line station, the call is routed to the SSP 105 of the called party where the AIN forwarding service trigger is set-off, the triggered SSP 105 formulates and sends the service request to the SCP 107, the SCP 107 determines that the called party has turned on the service and has set a particular wireless station as the destination station, the SCP 107 sends appropriate call processing instructions including a telephone number of the destination station to the SSP 105, and the SSP 105 forwards the call to the destination station.
Now, if it is the case in the scenario that the destination station is not on, is busy, or otherwise cannot answer the forwarded call, the call may then be forwarded back to the SSP 105 for further processing, such as for example forwarding the call to the originally called wire line station or a voice mail system, Plainly, such circuitous routing of the call employs many telephone network resources over an extended period of time.
Accordingly, a need exists for a system that forwards a call based on a determination beforehand of the status of the destination station. More particularly, a need exists for such a system that first determines whether the destination station is available, and only if so in fact forwards the call to such destination station. Thus, circuitous and costly routing of a call is avoided in the event the destination station is not available to answer the call.